Revision 1.02 – April 12, 2007
S5920 – PCI Product: Operation Registers
Data Book
This register controls the configuration for Pass-Thru
Regions 1-4.
ADD-ON PASS-THRU CONFIGURATION
REGISTER (APTCR)
Byte 0 Controls Pass-Thru Region 1
Byte 1 Controls Pass-Thru Region 2
Byte 2 Controls Pass-Thru Region 3
Byte 3 Controls Pass-Thru Region 4
Pass-Thru Configuration Register
Register Name:
Add-On Address:
Power-up value:
Add-On Attribute:
Size:
60h
80808080h
Read/Write
32 bits
IMPORTANT NOTE: This register (APTCR) is physi-
cally the same as the PCI Pass-Thru configuration
register (PTCR). It is intended that either the PCI sys-
tem or local Add-On interface will write to this register,
but not both. However, in the event that both the PCI
and Add-On write to this register, whichever side wrote
last wins. This register is also intended to be initialized
once, prior to any PCI bus operations. Pass-Thru
operation cannot be guaranteed if this register is
updated while a Pass-Thru transaction is being
performed.
Figure 35. Pass-Thru Configuration Register
31
24 23
16 15
8 7
0
Region 4
Region 3
Region 2
Region 1
Active Mode Wait States
D2 D1 D0
D7 Pass-Thru Mode
0 - PTADR# Not Driven
1 - PTADR# Driven
000 - 0 Wait States
001 - 1 Wait States
010 - 2 Wait States
011 - 3 Wait States
100 - 4 Wait States
101 - 5 Wait States
110 - 6 Wait States
111 - 7 Wait States
D6 Endian Conversion
0 - No Conversion
1 - Big Endian Conversion
D5 Write FIFO
0 - Enabled
1 - Disabled
Prefetch
D4 D3
00 - Disabled
01 - Small
10 - Medium
11 - Large
AMCC Confidential and Proprietary
DS1596
89
AMCC [ APPLIED MICRO CIRCUITS CORPORATION ]
